Testing with Real Robot#

Prerequisites#

  • The WMX ROS2 workspace is built and sourced

  • LMX(WMX Runtime) is installed at /opt/lmx/

  • EtherCAT cable is connected between compute platform and first servo drive

  • Robot and all servo drives are powered on

  • You have sudo privileges

EtherCAT Wiring#

┌──────────────┐    Ethernet     ┌──────────┐    ┌──────────┐         ┌──────────┐
│  Compute PC  │────(EtherCAT)──►│ Servo J1 │───►│ Servo J2 │── ... ──│ Servo J6 │
│  (dedicated  │                 └──────────┘    └──────────┘         └──────────┘
│   NIC port)  │
└──────────────┘

  • Use a dedicated Ethernet port for EtherCAT

  • Servo drives are daisy-chained (each drive has IN and OUT ports)

  • The I/O module for gripper control is part of the same chain

Configuration#

Platform

Config File

Launch File

Intel x86_64

intel_manipulator_config_cr3a.yaml

wmx_ros2_intel_manipulator_cr3a.launch.py

NVIDIA Jetson Orin

orin_manipulator_config_cr3a.yaml

wmx_ros2_orin_manipulator_cr3a.launch.py

Important

Update the wmx_param_file_path in the config YAML to match your actual home directory and workspace path.

Launch Commands#

sudo --preserve-env=PATH \
     --preserve-env=AMENT_PREFIX_PATH \
     --preserve-env=COLCON_PREFIX_PATH \
     --preserve-env=PYTHONPATH \
     --preserve-env=LD_LIBRARY_PATH \
     --preserve-env=ROS_DISTRO \
     --preserve-env=ROS_VERSION \
     --preserve-env=ROS_PYTHON_VERSION \
     --preserve-env=ROS_DOMAIN_ID \
     --preserve-env=RMW_IMPLEMENTATION \
     bash -c "source /opt/ros/${ROS_DISTRO}/setup.bash && \
              source ~/wmx_ros2_ws/install/setup.bash && \
              ros2 launch wmx_ros2_package wmx_ros2_cr3a_manipulator.launch.py \
              use_sim_time:=false"

Startup Sequence#

When launched, three nodes initialize in parallel:

  1. Device creation – Each node creates a WMX device handle

  2. EtherCAT scan – Network scan discovers all servo drives

  3. Communication start – Real-time EtherCAT communication begins

  4. Parameter loading – Gear ratios and axis polarities loaded from XML

  5. Servo enable – All 6 joint servos cleared and enabled

  6. Ready – All nodes report ready

Verifying the Connection#

ros2 node list          # Expect: 3 nodes
ros2 topic hz /joint_states   # Expect: ~500 Hz
ros2 topic echo /joint_states --field position  # Live joint positions
ros2 service call /wmx/engine/get_status std_srvs/srv/Trigger  # Expect: "Communicating"
ros2 action list        # Expect: follow_joint_trajectory

Gripper Control#

# Close gripper
ros2 service call /wmx/set_gripper std_srvs/srv/SetBool "{data: true}"

# Open gripper
ros2 service call /wmx/set_gripper std_srvs/srv/SetBool "{data: false}"

Shutdown#

Press Ctrl+C in the launch terminal. The nodes will automatically disable servos, stop EtherCAT communication, and close the WMX device.